As if it weren't clear enough already, Microsoft's new Zune HD media players are lining up toe-to-toe, feature-to-feature with Apple's iPod Touch.

The latest proof? Microsoft's devices will apparently include a marketplace for third-party applications.

That revelation came into focus over the weekend when several users reported seeing an "Apps" item on the menu in demo units of the Zune HDs on view at Best Buy stores. While the demo Zunes were apparently unable to connect to the marketplace that would sell third-party apps, the menu item strongly implies that feature will be available at launch or soon after.

Microsoft (NASDAQ: MSFT) was noncommittal.

"We don't have anything to share right now," a company spokesperson told InternetNews.com.

Microsoft confirmed earlier this month that the Zune HDs will launch on Sept. 15 at prices that aim to undercut Apple's (NASDAQ: AAPL) iPod Touch.

Contributors to several technology enthusiast sites spotted the menu item, including Zunited.net and Engadget.com. At least one enterprising potential buyer was quick enough to capture a snap of the menu on his camera phone.

Plenty of questions remain, however. At this point, it's unclear whether the availability of third-party Zune HD applications will have to wait until the end of the year for the official launch of Marketplace for Mobile, Microsoft's bid to compete with Apple's App Store, or whether Microsoft has some other as yet unannounced marketplace in mind.

Meanwhile, Apple claims its App Store already offers 65,000 applications, though many are not for iPods. Apple also boasts that it has garnered more than 1.5 billion downloads in the slightly more than a year since it launched, and signed up 100,000 developers to build apps for the iPhone.

Microsoft confirmed in May that the new units will feature a built-in HD Radio receiver, high-definition video output capabilities, organic light-emitting diode (OLED) touch screen, Wi-Fi, and an Internet browser.

In the meantime, Apple is rumored to be ready to launch new iPod Touch devices that include a built-in camera on Sept. 9, 2009, or 9-9-09, less than a week ahead of the Zune HD launch.